Cover Flow

In the haste to comply with VGB, some operators have forgotten the importance of flow rate. Is your facility one of them?

REINVENTING AQUATICS

Confused about the VGB Act?

Kathleen Reilly from CPSC will explain exactly what pools, waterparks and
resorts must do for proper compliance — and what they don't
have to worry about. Her seminar is just one part of our
Reinventing Aquatics virtual conference launching Nov. 10. For more
information and to sign up, go to aquaticsvirtualconf.com.

Lately, it seems the only news we hear
involving facility construction and aquatics management relates to
the enactment and enforcement of the Virginia Graeme Baker Pool and
Spa Safety Act.

By some accounts, approximately 40 percent of aquatics facilities
nationwide have complied with the new legislation as new and
innovative product solutions have been (and still are) being
introduced into the market. That means the remaining 60 percent of
pool builders and facility managers must work quickly to bring
their facilities into compliance.

But in their haste to comply, some important and basic
water-quality management rules have been forgotten. Consider a new,
commonly used phrase that’s recently entered our vocabulary
— “swapping plastic.” This term refers to simply
changing an existing suction outlet cover with a new VGB-certified
cover. However, merely “swapping plastic” has become a
catalyst for other problems.

Guidelines for flow rates, sump design and other considerations
have been fully outlined within the law. But some have perceived
these guidelines as nuances, resulting in negative press,
water-quality issues — and even entrapment risks on
improperly installed VGB-certified covers.

For example, one of the largest cities in Florida recently was
forced to close three of its public pools due to problems that
arose from efforts to comply with the VGB. To the city's credit,
the necessary steps were taken to replace existing covers with
approved products. However, the city's actions addressed only part
of the legislation and resulted in another equally serious problem,
which stemmed from the attempted retrofitting.

The VGB-certified covers the city installed to achieve
compliance were undersized and did not allow the correct flow to
filter the water properly. By exceeding the maximum flow rate (as
required to be stamped on each cover), the grates were no longer
certified as tested, thereby rendering the facility out of
compliance. Moreover, by installing a cover that had a
substantially reduced flow rate, the city caused an equally
hazardous situation of unsafe water chemistry.

An important part of the testing that determines whether a cover
is certified depends on the velocity at which the water flows
through the grate. Body entrapment and hair entanglement, two of
the five forms of entrapment, are directly related to the cover's
maximum allowable flow rate, sump configuration and associated
piping. Installing a cover with a flow rate less than needed and
operating the pool at a higher velocity completely negates the
certification and approval of the cover.

State and local health departments require a certain turnover
rate for a pool or spa. This allows proper filtration and
disinfection of the water. The turnover rate is simply the time it
takes for every gallon of water in a swimming pool or spa to be
cycled through the filtration system while the water is being
chemically balanced. This rate varies from 15 minutes for a spa to
six hours for a lap or diving pool. The label given to submerged
suction outlet covers defines the role they play in the
recirculation of large amounts of water in such a short time.

For existing pools, an evaluation from a design professional
should be performed to match the compliant cover with the turnover
rate of the pool being retrofitted. Another factor in determining
whether a cover is properly sized is the depth and size of the sump
and associated piping. Without a complete evaluation of these three
elements, the suction outlet cover may not meet the intent of the
law and actually create additional hazards.

In new construction, most design teams are specifying complete
grate and sumps that were tested as a single system. With the focus
of the certification process being on entrapment, fasteners and
flow rates, a complete system eliminates the need for any other
type of field approval or sign-off. For the design-build
contractor, a single system eliminates the need to source a design
professional for the necessary approvals because the liability
rests on the shoulders of the manufacturer.

The Virginia Graeme Baker Pool and Spa Safety Act was written to
regulate commercial pools and spas. Because the law prohibits the
manufacturing, distribution, and sale of noncompliant products
within the United States, the certified covers eventually will make
their way into the residential market. Though products are becoming
more available for almost all situations, in the end, the overall
costs associated with bringing a pool or facility into compliance
can be a large undertaking.

It is important to avoid those who are exploiting the law and
are only interested in “swapping plastic.” As with any
update or repair needed for a pool, doing the necessary homework
and hiring a reputable company can save time and money.

Even more important is ensuring that the replacement covers are
properly manufactured and in line with the intent of the new
legislation. This will give facility operators the peace of mind
that comes from knowing that their pools will provide a safe and
enjoyable experience for everyone.